China's Anbang Insurance Group has launched an improved takeover bid for Starwood Hotels & Resorts Worldwide Inc, pitting it against Marriott International in the quest for the US hotel chain.

The bidding war for Starwood heated up when a consortium led by Anbang Insurance gave a non-binding all-cash offer that valued Starwood at $14 billion.

The consortium, which includes private equity firms J.C. Flowers & Co and Primavera Capital Ltd, has offered $82.75 per share, topping the offer of $78 per share made by Marriott on March 21.

Starwood, which had accepted Marriott's $13.6 billion cash-and-stock offer, said it is weighing Anbang's offer.

It said the Anbang consortium's offer was "reasonably likely" to lead to a superior proposal.

A Starwood-Marriott merger would create the world's largest lodging company with about 5,700 hotels. Marriott said in a statement it was "confident that the previously announced amended merger agreement is the best course for both companies."

Shopping spree

Anbang is on a shopping spree in the US, armed with a $254 billion war chest. The Insurance giant said earlier this month it was acquiring another top dollar hotel property in the United States -- Strategic Hotels & Resorts -- for $6.5 billion.

Anbang had completed in 2015 the purchase of New York's storied Waldorf Astoria hotel from Hilton Worldwide Holdings for $1.95 billion.

Privately held Anbang had bought last year US annuities and life insurer Fidelity & Guaranty Life for $1.57 billion.

Anbang, a relatively small Chinese insurance company, punched above its weight to purchase iconic Waldorf Astoria, raising eyebrows in the US. The company was founded in 2004 with capital of $60 million. Its chairman, Wu Xiaohui, is married to the grand-daughter of Deng Xiaoping, the Economist reported.